Pablea 
• 1cn   Studies   no. 7 

By 

C ."» .    V^ood worth 


f    v 


UNIVERSITY  OF  CALIFORNIA 

AT   LOS  ANGELES 


i     M   P/O\A/CM 

PNIVEBSITY  OF  CALIFORNIA  PUBLICATIONS 

COLLEGE  OF  AGRICULTURE 

AGRICULTURAL  EXPERIMENT  STATION 

BERKELEY,  CALIFORNIA 


NEW   DOSAGE  TABLES 

FUMIGATION  STUDIES,  No.  7 


BY 

C.  W.  WOODWORTH 


BULLETIN  No.  257 

Berkeley,  Cal.,  July,  1915 


UNIVERSITY  OF  CALIFORNIA  PRESS 
BERKELEY 
1915 


BENJAMIN  IDE  WHEELER,  President  of  the  University. 
EXPERIMENT    STATION    STAFF 
HEADS   OP  DIVISIONS 

THOMAS  FORSYTE  HUNT,  Director. 

EUGENE  W.  HILGARD,  Agricultural  Chemistry  (Emeritus). 

EDWARD  J.  WICKSON,  Horticulture  (Emeritus). 

HERBERT  J.  WEBBER,  Director  Citrus  Experiment  Station;  Plant  Breeding. 

HUBERT  E.  VAN  NORMAN,  Vice-Director;  Dairy  Management. 

WILLIAM  A.  SETCHELL,  Botany. 

MEYER  E.  JAFFA,  Nutrition. 

EGBERT  H.  LOUGHRIDGE,  Soil  Chemistry  and  Physics  (Emeritus). 

CHARLES  W.  WOODWORTH,  Entomology. 

RALPH  E.  SMITH,  Plant  Pathology. 

J.  ELIOT  COIT,  Citriculture. 

JOHN  W.  GILMORE,  Agronomy. 

CHARLES  F.  SHAW,  Soil  Technology. 

JOHN  W.  GREGG,  Landscape  Gardening  and  Floriculture. 

FREDERIC  T.  BIOLETTI,  Viticulture  and  Enology. 

WARREN  T.  CLARKE  Agricultural  Extension. 

JOHN  S.  BURD,  Agricultural  Chemistry. 

CHARLES  B.  LIPMAN,  Soil  Chemistry  and  Bacteriology. 

CLARENCE  M.  HARING,  Veterinary  Science   and  Bacteriology. 

ERNEST  B.  BABCOCK,  Genetics. 

GORDON  H.  TRUE,  Animal  Husbandry. 

JAMES  T.  BARRETT,  Plant  Pathology. 

FRITZ  W.  WOLL,  Animal  Nutrition. 

A.  V.  STUBENRAUCH,  Pomology. 

WALTER  MULFORD,  Forestry. 

W.  P.  KELLEY,  Agricultural  Chemistry. 

H.  J.  QUAYLE,  Entomology. 

D.  T.  MASON,  Forestry. 

J.  B.  DAVIDSON,  Rural  Engineering. 

ELWOOD  MEAD,  Rural  Institutions. 

WILLIAM  G.  HUMMEL,  Agricultural  Education. 

LEON  M.  DAVIS,  Dairy  Industry. 

JOHN  E.  DOUGHERTY,  Poultry  Husbandry. 

FRANK  ADAMS,  Irrigation  Practice. 

DAVID  N.  MORGAN,  Assistant  to  the  Director. 

Mrs.  D.  L.  BUNNELL,  Librarian. 

DIVISION  OF  ENTOMOLOGY 

C.  W.  WOODWORTH  L.  J.  NICKELS 

W.  B.  HERMS  E.    O.  ESSIG 

E.  C.  VAN  DYKE  S.  B.  FREEBORN 

GEO.  A.  COLEMAN  E.  P.  VAN  DUZEE 

GEO.  P.  GRAY  M.  R.  MILLER 


355 


NEW  DOSAGE  TABLES 

BY  C.   W.  WOODWORTH 


A  new  principle  applicable  to  the  construction  of  dosage  tables 
was  discovered  while  making  a  careful  comparison  of  the  rate  of 
charge  in  the  dose  necessary  to  compensate  for  the  differences  in 
leakage. 

Since  large  tents  contain  a  greater  volume  of  gas  in  proportion  to 
the  surface  than  smaller  tents  the  leakage  is  correspondingly  less 
important  and  it  is  possible  to  arrange  a  series  of  sizes  of  tents  which 
will  correspond  with  the  various  degrees  of  leakage  in  such  a  manner 
that  they  should  require  identical  doses. 

Such  a  series,  omitting  the  fraction,  is  as  follows : 
37        35        32        30        28        26        24  ft. 
.10       .15       .20       .25       .30       .35       .40  % 

A  further  inspection  brought  out  the  fact  that  while  these  num- 
bers do  not  form  a  regular  simple  series  the  doses  that  are  assigned 
to  these  sizes  under  the  same  tent  do  form  a  regular  geometrical  pro- 
gression decreasing  at  such  a  rate  that  after  five  intervals  the  num- 
ber is  reduced  by  one  half. 

The  principle  is  then  that  an  arithmetical  series  of  leakages  is 
related  to  a  geometrical  series  of  dosages  and  both  correspond  to  the 
same  complex  series  of  sizes  of  tents. 

The  application  of  this  principle  to  the  construction  of  dosage 
tables  resulted  in  the  production  of  the  remarkably  simple  and  prac- 
tical form  presented  below.  It  is  necessary  to  point  out  again  that 
there  is  urgent  need  of  a  series  of  new  and  acceptable  tables. 

One  of  the  causes  of  the  continued  dissatisfaction  with  the  process 
of  fumigating  citrus  trees  is  the  common  use  of  dosage  tables  that 
are  grossly  inaccurate.  It  is  difficult  to  understand  why  these  should 
be  so  persistently  advocated  unless  it  be  that  their  inaccuracy  has 
not  been  sufficiently  emphasized. 

The  tables  most  in  use  are  incorrect  in  the  three  following  par- 
ticulars. 

I.     SHAPE 

The  range  of  shape  found  in  the  extensive  series  of  measurements 
made  by  this  station  varied  between  tents  in  which  the  distance  over 
equaled  that  around  the  tent  in  the  case  of  high  seedling  orange  trees 
to  the  low  broad  lemons  which  had  a  circumference  twice  that  of  the 
distance  over  the  top. 


238690 


4  UNIVERSITY    OF    CALIFORNIA EXPERIMENT    STATION 

A  very  prevalent  form  of  table  determines  the  relative  doses  in 
proportion  of  the  product  of  the  two  dimensions.  Thus  a  tree  30  x 
30  ft.  would  have  the  same  dose  as  one  21  x  42  ft.  This  is  evidently 
only  a  mathematical  blunder  and  is  about  equivalent  to  insisting  that 
a  man  six  feet  high  and  three  feet  waist  measure  weighed  the  same  as 
another  man  four  feet  around  and  four  and  one  half  feet  high,  since 
the  product  in  each  case  is  18. 

The  inaccuracy  of  this  method  of  calculating  is  perhaps  better 
shown  by  the  accompanying  diagram  (Fig.  1),  in  which  the  difference 
in  size  is  very  evident  to  the  eye. 


Fig.  1. — Extreme  shapes  of  trees.  Those  at  the  left  are  of 
equal  size  and  should  receive  equal  doses.  Those  at  the  right 
receive  the  same  dose  by  the  common  tables  but  one  is  a  third 
larger  than  the  other. 

The  distance  over  the  top  is  the  most  significant  dimension  since 
it  varies  with  changes  either  in  height  or  width.  Every  foot  of  decrease 
of  this  dimension  requires  approximately  four  feet  of  increase  in 
circumference  to  maintain  the  tree  of  the  same  size.  This  is  true 
whether  the  calculations  are  made  on  .the  basis  of  cubic  contents  or 
of  tent  area. 

The  dimensions  corresponding  with  each  foot  change  in  distance 
over  are  as  follows : 

30  x  30,  29  x  34,  28  x  38,  27  x  42,  26  x  46,  25  x  50. 
This  is  very  different  from  the  common  figures : 

30  x  30,  29  x  31,  28  x  32,  27  x33,  26  x  35,  25  x  36,  24  x  37,  23  x  39, 

and  22  x  41, 
which  are  in  no  wav  defensible  and  should  be  discarded. 


II.     SIZE 

The  writer  acknowledges  the  responsibilitj^  of  having  first  suggested 
the  method  of  size  calculation  now  in  vogue,  though  it  had  previously 
been  used  unconsciously  by  the  late  Alexander  Craw  and  some  who 


NEW    DOSAGE    TABLES  5 

have  adopted  it  subsequently  were  not  aware  of  the  identity  of  their 
method  of  calculation.  The  prevailing  plan  is  to  vary  the  dose  at  the 
same  rate  as  the  tent  area  varies.  That  is,  a  ten-foot  tree  receives  four 
times  as  much  as  a  five-foot  tree  and  has  four  times  as  much  tent  area. 
Each  square  foot  of  tent  area  by  this  plan  may  allow  the  same  amount 
of  gas  to  escape  before  the  tent  is  empty,  no  matter  what  the  size  of 
the  tree. 

How  completely  incorrect  this  plan  is  can  be  appreciated  by  extend- 
ing the  table  to  trees  of  very  large  size.  The  amount  per  cubic  foot 
is  half  as  large  in  a  ten-foot  tree  as  in  a  five-foot  tree  and  a  quarter 


Fig.  2. — Sizes  of  trees  that  receive  20,  7  and  2  oz.  respectively. 
The  medium  size  tree  has  the  same  dose  in  all  tables.  At  both 
extremes  the  correct  size  is  smaller  than  those  given  in  the  com- 
mon tables,  therefore  the  doses  in  the  common  tables  are  much 
too  weak. 


as  dense  in  a  twenty-foot,  an  eight  in  a  forty-foot,  etc.  Evidently  the 
initial  density  will  soon  come  to  be  so  low  as  to  be  completely  inefficient. 

The  calculation  of  the  dose  by  this  method  is  not  far  wrong  for 
trees  of  medium  size  and  the  plan  served  a  useful  purpose  as  long 
as  there  was  nothing  better,  but  it  is  now  clearly  time  to  discard  what 
was  from  the  first  given  as  a  tentative  makeshift  to  be  used  until  a 
better  method  was  worked  out. 

The  method  gives  in  fact  doses  that  are  too  weak  at  both  ends  of 
the  table  and  most  of  the  tables  have  been  arbitrarily  increased  at  the 
lower  end  to  accord  with  the  experience  of  fumigators  which  has 
abundantly  shown  the  weakness  of  the  calculated  tables. 

The  tables  which  follow  give  a  much  more  accurate  determination 
of  the  doses  and  these  are  conspicuously  different  both  for  large  and 
for  small  trees  as  shown  in  Figure  2. 


6  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION 

III.     LEAKAGE 

A  fundamental  defect  of  the  area  calculations  is  that  they  only 
provide  approximately  correct  doses  for  a  rather  small  range  of  sizes 
and  of  degrees  of  leakage.  Every  one  will  appreciate  that  since  a 


Fig.  3. — The  size  of  a  rent,  more  than  a  foot  long  in  an  average 
tree,  that  requires  a  15%  increase  in  dose,  the  same  would  be 
given  for  the  larger  tent  shown  in  outline.  One  degree  (.05%) 
on  the  leakage  meter  is  equivalent  to  a  rent  of  this  size. 

comparatively  tight  tent  will  require  doses  on  a  volume  basis  and 
tents  with  average  size  and  leakage  on  an  area  basis  that  other  degrees 
of  leakage  will  not  be  properly  provided  for  by  either  of  the  systems. 
If  a  tent  is  tighter  than  the  average  it  is  not  correct  to  simply  reduce 
all  doses  proportionately,  as  given  on  the  ordinary  table,  since  such 
&  process  preserves  the  same  system.  For  instance,  if  a  five  and  a 


NEW    DOSAGE    TABLES  7 

ten-foot  tree  received  respectively  four  and  sixteen  ounces,  a  reduc- 
tion of  25%  would  give  3  and  12,  which  have  the  same  relation,  that 
is,  one  is  four  times  the  other.  2  and  12  might  be  nearer  correct,  which 
would  be  in  proportion  of  1  to  6,  intermediate  between  the  1  to  4  area 
basis  and  the  volume  basis  of  1  to  8.  Likewise  for  a  more  leaky  tent 
a  25%  increase,  making  5  and  20  ounces,  should  more  likely  read  10 
and  20.  However,  if  the  tables  were  constructed  according  to  the 
right  system  as  regards  the  relation  of  size  to  dose  a  percentage  increase 
or  decrease  would  result  in  the  correct  adjustment  for  different  leak- 
ages. The  error  in  the  calculation  of  the  table  is  exactly  of  the  same 
character  as  that  regarding  size  and  leakage. 

Since  the  invention  of  the  leakage  meter  we  have  a  ready  means 
of  learning  just  what  the  natural  leakage  of  a  tent  is,  and  should 
regulate  our  dose  accordingly.  Standing  on  the  inside  of  the  tent 
one  can  see,  between  the  interlacing  of  the  fibres  of  the  weave  of  the 
cloth,  hundreds  of  thousands  of  openings;  though  small  enough  to 
prevent  the  passage  of  drops  of  water,  they  are  very  large  compared 
with  the  size  of  the  gas  particles  which  escape  through  these  holes 
without  any  hindrance.  In  dry  weather  the  fibres  shrink,  leaving 
larger  openings  which  the  meter  will  detect  and  measure,  but  to  com- 
pensate for  which  the  dose  should  be  larger. 

The  diagram  (Fig.  3)  will  show  graphically  the  significance  of 
leakage.  The  average  tent  is  equivalent  to  a  tight  tent  with  five  rents 
as  large  as  the  one  here  figured  and  many  tents  are  operating  with 
a  leakage  as  great  as  eight  such  openings  and  others  as  small  as  two. 
One  will  make  a  fuss,  and  rightly  so,  if  a  fumigator  uses  a  tent  with  a 
number  of  acid  burns  big  enough  to  put  his  fist  through,  but  will  very 
complacently  permit  the  use  of  a  tent  with  a  natural  leakage  ten  times 
as  great.  Natural  leakage  cannot  be  wholly  prevented  but  should  be 
measured  and  compensated  for  by  increased  dosage  and  when  this  is 
done  tables  properly  calculated  for  dosage  should,  by  all  means,  be 
used. 

Where  the  Common  Tables  Are  Right 

While  the  common  tables  are  calculated  on  wrong  principles  it 
should  be  remembered  that  the  doses  for  average-sized  trees  of  average 
shape  and  for  tents  with  average  leakage,  are  correct  and  that  serious 
inaccuracies  only  occur  when  these  average  conditions  are  departed 
from,  and,  furthermore,  it  may  frequently  happen  that  errors  com- 
pensate each  other,  where,  as  in  this  case,  there  are  three  different 
kinds  of  errors  varying  independently  of  each  other.  The  satisfactory 


8  UNIVERSITY    OF    CALIFORNIA — EXPERIMENT    STATION 

results  usually  obtained  by  the  use  of  the  common  tables  have  tended 
to  blind  the  users  to  this  cause  of  occasional  bad  results.  The  use  of 
a  better  calculated  table  will  in  no  way  improve  the  results  under  these 
normal  conditions. 

Construction  of  the  New  Tables 

The  following  method  was  employed  in  the  construction  of  the 
tables  given  below.  The  dose  column  was  made  by  using  the  num- 
bers 5,  6,  7,  8,  9,  and  10  oz,  and  halving  and  doubling  the  same  so  as  to 
maintain  the  same  ratios  through  the  whole  length  of  the  column.  The 
average  difference  is  almost  exactly  14%  increase  or  15%  decrease. 

The  next  column  gives  the  dimensions  in  feet  for  tents  in  which  the 
distance  around  equals  the  distance  over  the  top  and  is  so  calculated 
that  there  should  be.  a  difference  of  14%  in  the  doses  the  adjacent 
sizes  should  receive.  The  calculation1  of  this  column  is  the  most  im- 
portant element  of  the  whole  table. 

Three  methods  of  calculation  have  been  proposed,  viz.,  volumne, 
area  and  leakage. 

The  volumne  method  was  used  in  all  the  older  tables  and  would 
require  a  little  less  than  5%  increase  in  size  for  each  line  on  the  table. 

The  area  method,  requiring  a  little  over  7%  per  line  is  that  now 
almost  universally  employed  and  is  somewhat  justified  on  the  ground 
that  it  approximately  allows  for  the  average  leakage  of  fumigation 
tent  material. 

The  leakage  method  used  in  this  table  allows  accurately  for  leak- 
age. The  average  increase  in  size  between  22  and  44  feet  is  precisely 
the  same  as  by  the  area  method,  but  the  upper  end  of  the  table  ap- 
proaches nearer  the  5%  and  the  lower  toward  the  14%.  This  method 
conforms  with  the  actual  practice  of  fumigators  who  find  it  necessary 
to  arbitrarily  modify  the  two  ends  of  the  common  table. 

The  remainder  of  the  table  gives  the  dimensions  of  trees  of  diff- 
erent shapes  but  approximately  the  same  sizes  and  which  should  there- 
fore receive  the  same  doses.  The  distance  over  the  top  of  the  tent  is 
given  in  black  type,  the  numbers  simply  being  arranged  consecutively 
and  beneath  each  the  corresponding  circumferences  are  written.  These 
differ  by  fours. 

Accuracy  of  the  Tables 

All  fractional  parts  have  been  omitted  in  these  tables.  The  dose 
series  is  actually  5,  5.7,  6.5,  7.5,  8.7,  and  10  oz.  A  slightly  more 
accurate  continuation  would  be  11,  13,  15,  18,  20,  22,  26,  30,  35,  and 


NEW    DOSAGE    TABLES  9 

40,  but  it  seemed  best  to  adhere-  strictly  to  the  round  numbers  since 
it  introduced  no  large  error.  In  the  size  column,  35  and  40  are  about 
0.4  too  high,  and  16  and  44,  0.3  or  0.4  too  low,  but  all  the  other  num- 
bers are  within  0.2  of  the  theoretical  value. 


Use  of  the  Tables 

These  tables  are  printed  in  large  type  so  as  to  be  easily  read  at 
night. 

All  combinations  receiving  the  same  dose  are  on  the  same  line 
and  cannot  therefore  be  confused. 

The  important  dimension  (the  distance  over  the  top),  is  given 
foot  by  foot,  making  it  possible  to  read  the  dose  accurately  and  rapidly. 
After  a  little  practice  one  can  read  the  dose  from  the  large  figures 
only  and  will  be  inclined  to  disregard  the  smaller  type.  The  rule 
is  as  follows  where  the  two  dimensions  differ :  For  adjacent  dimensions 
the  dose  is  opposite  the  lower  number,  otherwise  it  is  opposite  the  one 
just  above,  unless  the  difference  is  six  or  more  lines,  that  is,  where  the 
dose  opposite  the  upper  number  is  more  than  twice  that  of  the  lower 
in  which  case  look  on  the  second  line  above  lower  size. 

The  tables  can  be  designated  by  the  upper  numbers,  thus  a  50-20 
table  means  that  a  tree  50  x  50  receives  a  20  oz.  dose. 

If  the  tents  show  .25%  leakage  and  it  is  decided  to  use  the  50-18 
table  the  tent  may  become  tighter  after  the  dew  falls  and  read  .20% 
leakage  when  it  will  be  safe  to  use  50-16  table,  but  on  the  other  hand 
if  a  dry  wind  increases  the  leakage  to  .30%  by  all  means  change  to  the 
50-20  table,  or  if  it  becomes  .35%  take  the  50-24  table. 

It  will  be  observed  that  all  these  new  tables  are  identical  except 
the  shifting  of  the  dose  column. 


Relation  to  Other  Tables 

Because  of  the  errors  in  calculation  in  the  common  tables,  pointed 
out  in  the  first  part  of  this  bulletin,  they  are  not  strictly  comparable 
with  chese  here  presented.  In  the  majority  of  the  doses  the  table  called 
110%  in  Circular  129  corresponds  closely  with  a  50-32  table,  the  100% 
with  50-28,  90%  with  50-24  and  the  75%  with  50-20;  the  last,  however, 
gives  some  doses  as  low  as  in  the  50-16  table  and  equally  large  errors 
occur  in  all. 


10 

UNIVERSITY  OF  CALIFORNIA  —  EXPERIMENT   STATION 

FUMIGATION  TABLE  —  SODIUM 

CYANID 

SIZES 

OF 

TENTS 

Feet 

Dose  oz. 

43 

78 

44 

74 

45 

70 

46 

66 

47 
62 

48 

58 

49 

54 

50 

-  32 

40 

75 

41 
71 

42 

67 

43 

63 

44 
59 

45 

55 

46 

51 

47 

-  28 

37 

38 

39 

40 

41 

42 

43 

MM 

f*m 

72 

68 

64 

60 

56 

52 

48 

TTT 

•  Z4 

36 

66 

37 

62 

38 

58 

39 

54 

40 

50 

41 

46 

42 

-20 

34 

64 

35 

60 

36 

56 

37 

52 

38 

48 

39 

44 

40 

-  18 

31 

61 

32 

57 

33 

53 

34 

49 

35 

45 

36 

41 

37 

-  16 

30 

55 

31 

51 

32 
47 

33 

43 

34 

39 

35 

-  14 

27 

28 

29 

30 

31 

"^  ^% 

1  ^ 

52 

48 

44 

40 

36 

\j  ^^ 

™    1  -- 

25 

50 

26 

46 

27 
42 

28 

38 

29 

34 

\j\j 

-  10 

24 

25 

26 

27 

^\{^ 

44 

40 

36 

32 

£Q 

22 

42 

23 

38 

24 

34 

25 

30 

26 

-    8 

20 

21 

22 

23 

oyi 

40 

36 

32 

28 

ZTT 

19 
34 

20 

30 

21 

26 

22 

-    6 

17 

32 

18 

28 

19 

24 

20 

-    5 

15 

30 

16 

26 

17 

22 

18 

- 

14 

15 

1  d 

24 

20 

lo 

13 

23 

14 

19 

15 

- 

11 
21 

12 
17 

13 

-    3 

NEW  DOSAGE  TABLES  11 

FUMIGATION  TABLE — SODIUM  CYANID 

SIZES  OF  TENTS  Feet  Dose  oz. 

43   44   45    46   47   48  49  j-A    OO 

78   74    70    66    62    58  54  OU  -  Zo 

40   41    42   43    44   45  46  A**   r*/t 

75   71    67    63    59    55  51  T1/  -  ^T1 

37   38    39    40   41    42  43 

72   68    64    60    56    52  48 

36    37    38    39    40  41  yi  ^    |  Q 

66    62    58    54    50  46  T"^  "  lO 

34    35    36   37    38  39  Af\    j  £% 

64    60    56    52    48  44  **U  -  ID 


44-20 


31    32    33    34    35    36 

61    57    53    49    45    41 


37-  14 


30    31    32    33  34  ^f-  j /* 

55    51    47    43  39  *X?  -  1^ 

27   28   29    30  31  ^f\  1  f\ 

52    48    44    40  36  3£  -  1U 

25    26    27    28  29  ^f\  rv 

50    46    42    38  34  «3U  ' 

24   25    26  27  90  Q 

44    40    36  32  ^O  '  O 

22    23    24  25  ryr*  ^ 

42    38    34  30  ^V)  / 

20   21    22  23  ^A  fc 

40    36    32  28  ^^  "  O 

19   20  21  ^^  C 

34    30  26  **&  "'  *J 

17    18  19  ^f\ 

32    28  24  &J  " 

15    16  17  10  A 

30    26  22  IO  -  "t 

14  15  1  fo 

24  20  1C  - 

13  14  1  C  ^  ^ 

23  19  !*->  *-> 

11  12  i  1 

21  17  1O  • 


12  UNIVERSITY  OF  CALIFORNIA EXPERIMENT  STATION 

FUMIGATION  TABLE — SODIUM  CYANID 


SIZES  OF  TENTS 

Feet    Dose  oz. 

43 

78 

44 

74 

45 

70 

46 

66 

47 

62 

48 

58 

49 

54 

50- 

24 

40 

75 

41 

71 

42 

67 

43 

63 

44 

59 

45 

55 

51 

47- 

20 

37 

72 

38 

68 

39 

64 

40 

60 

41 

56 

42 

52 

43 

48 

44- 

18 

36 

66 

37 

62 

38 

58 

39 

54 

40 

50 

46 

42- 

16 

34 

64 

35  ? 
60 

36 

56 

37 

52 

38 

48 

44 

40- 

14 

31 

61 

32 

57 

33 

53 

34 

49 

35 

45 

41 

37- 

12 

30 

55 

31 

51 

32 

47 

33 

43 

34 

39 

35- 

10 

27 
52 

28 

48 

29 

44 

30 

40 

31 

36 

32- 

9 

25 

26 

27 

28 

29 

^Jf\ 

50 

46 

42 

38 

34 

*5(J  • 

• 

24 

25 

26 

27 

10 

44 

40 

36 

32 

Zo  - 

22 

23 

24 

25 

^ 

42 

38 

34 

30 

2v3  - 

20 

21 

22 

23 

1/1 

40 

36 

32 

28 

^T:  ™ 

19 

20 

21 

OO 

34 

30 

26 

««  ~ 

17 

32 

18 

28 

19 

24 

20- 

4 

15 

30 

16 

26 

17 
22 

18- 

14 

24 

15 

20 

16- 

3 

13 

23 

14 

19 

15- 

11 

12 

1  ~* 

21 

17 

lO  ™ 

NEW    DOSAGE    TABLES  13 

FUMIGATION  TABLE — SODIUM  CYANID 


SIZES 

OF 

TENTS 

Feet          Dose  oz. 

43 

78 

44 

74 

45 

70 

46 

66 

47 
62 

48 

58 

49 

54 

50-20 

40 

75 

41 

71 

42 

67 

43 

63 

44 
59 

45 

55 

46 

51 

47-  18 

37 

72 

38 

68 

39 

64 

40 

60 

41 
56 

42 

52 

43 

48 

44-  16 

36 

37 

38 

39 

40 

41 

66 

62 

58 

54 

50 

46 

34 

35 

36 

37 

38 

39 

j.n     i  ^ 

64 

60 

56 

52 

48 

44 

TiU  ™   1  — 

31 

61 

32 

57 

33 

53 

34 

49 

35 

45 

36 

41 

37-  10 

30 

55 

31 

51 

32 
47 

33 

43 

34 

39 

35-    9 

27 
52 

28 

48 

29 
44 

30 

40 

31 

36 

^2O            Q 
O^  "       O 

25 

26 

27 

28 

29 

^n       7 

50 

46 

42 

38 

34 

%3U  ™      / 

24 

25 

26 

27 

/^o           /^ 

44 

40 

36 

32 

—  o  "      O 

22 

23 

24 

25 

r\r+             j- 

42 

38 

34 

30 

^D  ™     O 

20 

21 

22 

23 

r\/\ 

40 

36 

32 

28 

^T1   ™ 

19 
34 

20 

30 

21 

26 

22-    4 

17 

18 

19 

r*f\ 

32 

28 

24 

£\J   ™ 

15 

16 

17 

1  ft             ^ 

30 

26 

22 

lO   ™       «3 

14 

15 

1  CZ, 

24 

20 

10  • 

13 

14 

1  EN 

23 

19 

13   ™ 

_; 

11 

12 

1  ~>            r\ 

21 

17 

1«3  ~      *i- 

14  UNIVERSITY  OF  CALIFORNIA— EXPERIMENT  STATION 

FUMIGATION  TABLE — SODIUM  CYANID 


SIZES  OF  TENTS 

Feet    Dose  oz. 

43 

78 

44 

74 

45 

70 

46 

66 

47 
62 

48 

58 

49 
54 

50- 

18 

40 

75 

41 
71 

42 

67 

43 

63 

44 

59 

45 

55 

46 

51 

47- 

16 

37 

72 

38 

68 

39 

64 

40 

60 

41 

56 

42 
52 

43 

48 

44- 

14 

36 

66 

37 

62 

38 

58 

39 

54 

40 

50 

41 

46 

42- 

12 

34 

64 

35 

60 

36 

56 

37 

52 

38 

48 

39 

44 

40- 

10 

31 

61 

32 

57 

33 

53 

34 

49 

35 

45 

36 

41 

37- 

9 

30 

31 

32 

33 

34 

55 

51 

47 

43 

39 

35  • 

27 
52 

28 

48 

29 

44 

30 

40 

31 

36 

32- 

7 

25 

50 

26 

46 

27 
42 

28 

38 

29 

34 

30- 

6 

24 

44 

25 

40 

26 

36 

32 

28- 

5 

22 

23 

24 

25 

42 

38 

34 

30 

26  - 

20 

21 

22 

23 

40 

36 

32 

28 

24  • 

4 

19 

20 

21 

T} 

34 

30 

26 

22  ™ 

17 

32 

18 

28 

19 

24 

20- 

3 

t 

15 

30 

16 

26 

17 
22 

18- 

. 

14 

24 

15 

20 

16- 

13 

14 

1  C 

_ 

» 

23 

19 

lO  " 

2, 

11 

21 

12 
17 

13- 

42    38    34    30 
20   21    22   23 

40    36    32    28 


NEW  DOSAGE  TABLES  15 

FUMIGATION  TABLE  —  SODIUM  CYANID 

SIZES  OF  TENTS  Feet          Dose  oz. 

43   44    45    46    47    48  49  CA    1  <2 

78   74    70    66    62    58  54  3U  -  1O 

40   41    42   43    44   45  46  A*J    \/\ 

75   71    67    63    59    55  51  T1/ 

37   38   39   40   41   42  43  A  A 

72   68    64    60    56    52  48 

36    37    38    39    40  41  JO    1  f\ 

66    62    58    54    50  46  t^  '   IV 

34    35    36    37    38  39  /t(\     Q 

64    60    56    52    48  44  ^V     & 

31    32    33    34    35  36  ^7     O 

61    57    53    49    45  41  «^/     O 

30    31    32    33  34  ^5  C     7 

55    51    47    43  39  ^^     / 

27   28   29   30  31 

52    48    44    40  36 

25    26    27    28  29  ^f|     C 

50    46    42    38  34  OU  '    O 

24   25   26  27 

44    40    36  32 

22   23   24  25  r       A 

*'   "t 


20        21        22        23        24 


19    20  21    99     ^l 

34    30  26    £*£  "   & 

17    18  19 

32    28  24 

15    16  17    10 

30    26  22    1O  " 

14  15    \fo     r> 

24  20    ID  *•   ^ 

13  14 

23  19 

11  12 

21  17 


23869O 


16  UNIVERSITY   OF  CALIFORNIA — EXPERIMENT   STATION 


RESUME 

A  new  principle  in  dosage  relationships  produces  a  simpler  form 
of  dosage  tables  than  any  hitherto  known. 

The  common  tables  are  grossly  inaccurate  in  their  method  of  com- 
putation. 

Extremes  in  shape  show  inconsistencies  as  high  as  33%. 

Both  high  and  low  trees  are  given  relatively  much  weaker  doses  than 
'trees  of  medium  size. 

Percentage  adjustments  for  varying  degrees  of  leakage  exhibit  the 
same  faults  in  the  common  tables  as  shown  regarding  sizes  of  trees. 

The  most  important  improvement  to  come  in  fumigation  practice 
is  the  general  adoption  of  correct  allowance  for  tent  leakage. 

All  three  sources  of  error  may  contribute  to  the  production  of  a 
very  faulty  estimate  of  dose  or  may  compensate  each  other  and  all 
tables  are  practically  sound  for  medium  conditions. 

The  construction  of  the  new  tables  involves  no  mathematical  diffi- 
culties except  for  the  calculation  of  the  series  of  18  sizes. 

The  tables  are  exceptionally  simple,  legible,  not  liable  to  confusion 
and  allow  for  all  needed  variations  of  strength  of  dose. 


UNIVERSITY  of  CALIFORNIA 

AT 

LOS  ANGELES 
LIBRARY 


Lithomount 

•    • 

SB 

955     Woodworth 
WB7n     New 


$s> 

555 

M&ln. 
tj^&. 


mmmSHSSKSS&t  L|BRARY  FACIl 


A     001  138 1  353 


This  book  is  DUE  on  the  last 
date  stamped  below 


